Lighting control apparatus of vehicle-purpose lighting device

• US 20070018586A1
• Filed: 07/19/2006
• Published: 01/25/2007
• Est. Priority Date: 07/20/2005
• Status: Active Grant

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Ishida, Hiroyuki, Ito, Masayasu, Uchiyama, Yoshihiro, Yagi, Seiichiro
• Granted Patent: US 7,825,599 B2
• Time in Patent Office: Days
• US Class Current: 315/79
• CPC Class Codes: B60Q 1/143 combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• CPC Class Codes: B60Q 2300/054 Variable non-standard intensity, i.e. emission of various beam intensities different from standard intensities, e.g. continuous or stepped transitions of intensity
• CPC Class Codes: B60Q 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/116 Vehicle at a stop
• CPC Class Codes: B60Q 2300/146 Abnormalities, e.g. fail-safe
• CPC Class Codes: H02M 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take precedence
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A lighting control apparatus of a vehicle-purpose lighting device can contribute power saving effect, and prevention of a deterioration of a semiconductor light source, and also, can maintain driving safety characteristics. When an input terminal becomes a low level while a vehicle is stopped, a PNP transistor is turned ON, so that a source current I1 flows through a current detecting terminal; a switching regulator lights an LED under beam attenuating operation of 70% in accordance with a light emitting degree capable of satisfying a luminous intensity distribution defined in a law; when an upper beam is lighted, the input terminal becomes a low level; a PNP transistor is turned ON; a source current I2 flows through the current detecting terminal, so that the light emitting degree of the LED is further decreased, and thus, the switching regulator lights the LED under beam attenuating operation of 50%.

Claims

1. A lighting control apparatus of a vehicle-purpose lighting device comprising:

light amount instruction value setting means to which information related to either a status of a vehicle or a lighting operation of a light source is inputted, the light amount instruction value setting means setting a light amount instruction value based on said information; and

electric power supplying means for supplying an input voltage from a power supply to a lower beam-purpose semiconductor light source in accordance with said light amount instruction value, wherein;

when information for indicating that a vehicle speed is lower than a predetermined speed value is inputted to said light amount instruction value setting means, said light amount instruction value setting means sets a light amount instruction value by which said lower beam-purpose semiconductor light source is lighted under beam-attenuating condition up to a light emitting degree capable of satisfying a predetermined luminous intensity distribution; and

when information for indicating that an upper beam-purpose light source is lighted is inputted to said light amount instruction value setting means, said light amount instruction value setting means sets a light amount instruction value such that a light emitting degree is lowered from that of said beam-attenuating lighting operation so as to light said lower beam-purpose semiconductor light source under beam-attenuating condition.

2. A lighting control apparatus of a vehicle-purpose lighting device as claimed in claim 1 wherein:

said light amount instruction value setting means includes a temperature detecting element for detecting an ambient temperature; and

when a temperature detected by said temperature detecting element reaches a predetermined temperature, said light amount instruction value setting means sets a light amount instruction value used to decrease the temperature of said lower beam-purpose semiconductor light source lower than, or equal to, a setting temperature, or sets a light amount instruction value used to restrict the temperature of said lower beam-purpose semiconductor light source to said setting temperature, which correspond to light amount instruction values used to reduce a light emitting degree of said lower beam-purpose semiconductor light source, and outputs any one of said set light amount instruction values to said electric power supplying means.

3. A lighting control apparatus of a vehicle-purpose lighting device as claimed in claim 2 wherein:

said light amount instruction value setting means sets a light amount instruction value when the temperature detected by said temperature detecting element reaches the predetermined temperature under such a condition that the information for indicating that said vehicle speed is lower than the predetermined speed value has been set; and

said light amount instruction value setting means prohibits setting of the light amount instruction amount when the temperature detected by said temperature detecting element reaches the predetermined temperature under such a condition that the information for indicating that said vehicle speed is lower than the predetermined speed value has not been set.

4. A lighting control apparatus of a vehicle-purpose lighting device comprising:

a semiconductor lower beam-purpose light source powered by an input voltage from an electric power supply;

control circuitry that changes an amount of the input voltage based on control information;

wherein the control information is at least one selected from the group consisting of a status of a vehicle, a lighting state of an upper beam-purpose light source, and an ambient temperature.

5. The lighting control apparatus of claim 4, wherein the control circuitry decreases the amount of the input voltage based on the control information of the status of the vehicle when the status of the vehicle indicates a vehicle speed lower than a predetermined speed value.

6. The lighting control apparatus of claim 4, wherein the control circuitry decreases the amount of the input voltage based on the control information of a lighting state of an upper beam-purpose light source when the lighting state of the upper beam-purpose light source indicates that the upper beam-purpose light source is lighted.

7. The lighting control apparatus of claim 4, wherein the control circuitry decreases the amount of the input voltage based on the control information of the ambient temperature when the ambient temperature is above a predetermined temperature value.

8. The lighting control apparatus of claim 5, wherein the control circuitry further decreases the decreased amount of the input voltage based on the control information of a lighting state of a light source when the lighting state of the light source indicates that the light source is lighted.

9. The lighting control apparatus of claim 7, wherein the control circuitry only decreases the amount of the input voltage based on the control information of the ambient temperature when the ambient temperature is above a predetermined temperature value when the control information of the status of the vehicle when the status of the vehicle indicates a vehicle speed lower than a predetermined speed value.